/*
** $Id: lobject.c,v 2.113.1.1 2017/04/19 17:29:57 roberto Exp $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/

#define lobject_c
#define LUA_CORE

#include "lprefix.h"

#include <locale.h>
#include <math.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "lua.h"

#include "lctype.h"
#include "ldebug.h"
#include "ldo.h"
#include "lmem.h"
#include "lobject.h"
#include "lstate.h"
#include "lstring.h"
#include "lvm.h"

LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};

/*
** converts an integer to a "floating point byte", represented as
** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
** eeeee != 0 and (xxx) otherwise.
*/
int luaO_int2fb(unsigned int x)
{
  int e = 0; /* exponent */
  if (x < 8)
    return x;
  while (x >= (8 << 4))
  {                     /* coarse steps */
    x = (x + 0xf) >> 4; /* x = ceil(x / 16) */
    e += 4;
  }
  while (x >= (8 << 1))
  {                   /* fine steps */
    x = (x + 1) >> 1; /* x = ceil(x / 2) */
    e++;
  }
  return ((e + 1) << 3) | (cast_int(x) - 8);
}

/* converts back */
int luaO_fb2int(int x)
{
  return (x < 8) ? x : ((x & 7) + 8) << ((x >> 3) - 1);
}

/*
** Computes ceil(log2(x))
*/
int luaO_ceillog2(unsigned int x)
{
  static const lu_byte log_2[256] = {/* log_2[i] = ceil(log2(i - 1)) */
                                     0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
                                     6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
                                     7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
                                     7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
                                     8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
                                     8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
                                     8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
                                     8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8};
  int l = 0;
  x--;
  while (x >= 256)
  {
    l += 8;
    x >>= 8;
  }
  return l + log_2[x];
}

static lua_Integer intarith(lua_State *L, int op, lua_Integer v1,
                            lua_Integer v2)
{
  switch (op)
  {
  case LUA_OPADD:
    return intop(+, v1, v2);
  case LUA_OPSUB:
    return intop(-, v1, v2);
  case LUA_OPMUL:
    return intop(*, v1, v2);
  case LUA_OPMOD:
    return luaV_mod(L, v1, v2);
  case LUA_OPIDIV:
    return luaV_div(L, v1, v2);
  case LUA_OPBAND:
    return intop(&, v1, v2);
  case LUA_OPBOR:
    return intop(|, v1, v2);
  case LUA_OPBXOR:
    return intop (^, v1, v2);
  case LUA_OPSHL:
    return luaV_shiftl(v1, v2);
  case LUA_OPSHR:
    return luaV_shiftl(v1, -v2);
  case LUA_OPUNM:
    return intop(-, 0, v1);
  case LUA_OPBNOT:
    return intop (^, ~l_castS2U(0), v1);
  default:
    lua_assert(0);
    return 0;
  }
}

static lua_Number numarith(lua_State *L, int op, lua_Number v1,
                           lua_Number v2)
{
  switch (op)
  {
  case LUA_OPADD:
    return luai_numadd(L, v1, v2);
  case LUA_OPSUB:
    return luai_numsub(L, v1, v2);
  case LUA_OPMUL:
    return luai_nummul(L, v1, v2);
  case LUA_OPDIV:
    return luai_numdiv(L, v1, v2);
  case LUA_OPPOW:
    return luai_numpow(L, v1, v2);
  case LUA_OPIDIV:
    return luai_numidiv(L, v1, v2);
  case LUA_OPUNM:
    return luai_numunm(L, v1);
  case LUA_OPMOD:
  {
    lua_Number m;
    luai_nummod(L, v1, v2, m);
    return m;
  }
  default:
    lua_assert(0);
    return 0;
  }
}

void luaO_arith(lua_State *L, int op, const TValue *p1, const TValue *p2,
                TValue *res)
{
  switch (op)
  {
  case LUA_OPBAND:
  case LUA_OPBOR:
  case LUA_OPBXOR:
  case LUA_OPSHL:
  case LUA_OPSHR:
  case LUA_OPBNOT:
  { /* operate only on integers */
    lua_Integer i1;
    lua_Integer i2;
    if (tointeger(p1, &i1) && tointeger(p2, &i2))
    {
      setivalue(res, intarith(L, op, i1, i2));
      return;
    }
    else
      break; /* go to the end */
  }
  case LUA_OPDIV:
  case LUA_OPPOW:
  { /* operate only on floats */
    lua_Number n1;
    lua_Number n2;
    if (tonumber(p1, &n1) && tonumber(p2, &n2))
    {
      setfltvalue(res, numarith(L, op, n1, n2));
      return;
    }
    else
      break; /* go to the end */
  }
  default:
  { /* other operations */
    lua_Number n1;
    lua_Number n2;
    if (ttisinteger(p1) && ttisinteger(p2))
    {
      setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
      return;
    }
    else if (tonumber(p1, &n1) && tonumber(p2, &n2))
    {
      setfltvalue(res, numarith(L, op, n1, n2));
      return;
    }
    else
      break; /* go to the end */
  }
  }
  /* could not perform raw operation; try metamethod */
  lua_assert(L != NULL); /* should not fail when folding (compile time) */
  luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
}

int luaO_hexavalue(int c)
{
  if (lisdigit(c))
    return c - '0';
  else
    return (ltolower(c) - 'a') + 10;
}

static int isneg(const char **s)
{
  if (**s == '-')
  {
    (*s)++;
    return 1;
  }
  else if (**s == '+')
    (*s)++;
  return 0;
}

/*
** {==================================================================
** Lua's implementation for 'lua_strx2number'
** ===================================================================
*/

#if !defined(lua_strx2number)

/* maximum number of significant digits to read (to avoid overflows
   even with single floats) */
#define MAXSIGDIG 30

/*
** convert an hexadecimal numeric string to a number, following
** C99 specification for 'strtod'
*/
static lua_Number lua_strx2number(const char *s, char **endptr)
{
  int dot = lua_getlocaledecpoint();
  lua_Number r = 0.0;        /* result (accumulator) */
  int sigdig = 0;            /* number of significant digits */
  int nosigdig = 0;          /* number of non-significant digits */
  int e = 0;                 /* exponent correction */
  int neg;                   /* 1 if number is negative */
  int hasdot = 0;            /* true after seen a dot */
  *endptr = cast(char *, s); /* nothing is valid yet */
  while (lisspace(cast_uchar(*s)))
    s++;                                                    /* skip initial spaces */
  neg = isneg(&s);                                          /* check signal */
  if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */
    return 0.0;                                             /* invalid format (no '0x') */
  for (s += 2;; s++)
  { /* skip '0x' and read numeral */
    if (*s == dot)
    {
      if (hasdot)
        break; /* second dot? stop loop */
      else
        hasdot = 1;
    }
    else if (lisxdigit(cast_uchar(*s)))
    {
      if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */
        nosigdig++;
      else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */
        r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
      else
        e++; /* too many digits; ignore, but still count for exponent */
      if (hasdot)
        e--; /* decimal digit? correct exponent */
    }
    else
      break; /* neither a dot nor a digit */
  }
  if (nosigdig + sigdig == 0) /* no digits? */
    return 0.0;               /* invalid format */
  *endptr = cast(char *, s);  /* valid up to here */
  e *= 4;                     /* each digit multiplies/divides value by 2^4 */
  if (*s == 'p' || *s == 'P')
  {                   /* exponent part? */
    int exp1 = 0;     /* exponent value */
    int neg1;         /* exponent signal */
    s++;              /* skip 'p' */
    neg1 = isneg(&s); /* signal */
    if (!lisdigit(cast_uchar(*s)))
      return 0.0;                    /* invalid; must have at least one digit */
    while (lisdigit(cast_uchar(*s))) /* read exponent */
      exp1 = exp1 * 10 + *(s++) - '0';
    if (neg1)
      exp1 = -exp1;
    e += exp1;
    *endptr = cast(char *, s); /* valid up to here */
  }
  if (neg)
    r = -r;
  return l_mathop(ldexp)(r, e);
}

#endif
/* }====================================================== */

/* maximum length of a numeral */
#if !defined(L_MAXLENNUM)
#define L_MAXLENNUM 200
#endif

static const char *l_str2dloc(const char *s, lua_Number *result, int mode)
{
  char *endptr;
  *result = (mode == 'x') ? lua_strx2number(s, &endptr) /* try to convert */
                          : lua_str2number(s, &endptr);
  if (endptr == s)
    return NULL; /* nothing recognized? */
  while (lisspace(cast_uchar(*endptr)))
    endptr++;                               /* skip trailing spaces */
  return (*endptr == '\0') ? endptr : NULL; /* OK if no trailing characters */
}

/*
** Convert string 's' to a Lua number (put in 'result'). Return NULL
** on fail or the address of the ending '\0' on success.
** 'pmode' points to (and 'mode' contains) special things in the string:
** - 'x'/'X' means an hexadecimal numeral
** - 'n'/'N' means 'inf' or 'nan' (which should be rejected)
** - '.' just optimizes the search for the common case (nothing special)
** This function accepts both the current locale or a dot as the radix
** mark. If the convertion fails, it may mean number has a dot but
** locale accepts something else. In that case, the code copies 's'
** to a buffer (because 's' is read-only), changes the dot to the
** current locale radix mark, and tries to convert again.
*/
static const char *l_str2d(const char *s, lua_Number *result)
{
  const char *endptr;
  const char *pmode = strpbrk(s, ".xXnN");
  int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0;
  if (mode == 'n') /* reject 'inf' and 'nan' */
    return NULL;
  endptr = l_str2dloc(s, result, mode); /* try to convert */
  if (endptr == NULL)
  { /* failed? may be a different locale */
    char buff[L_MAXLENNUM + 1];
    const char *pdot = strchr(s, '.');
    if (strlen(s) > L_MAXLENNUM || pdot == NULL)
      return NULL;                            /* string too long or no dot; fail */
    strcpy(buff, s);                          /* copy string to buffer */
    buff[pdot - s] = lua_getlocaledecpoint(); /* correct decimal point */
    endptr = l_str2dloc(buff, result, mode);  /* try again */
    if (endptr != NULL)
      endptr = s + (endptr - buff); /* make relative to 's' */
  }
  return endptr;
}

#define MAXBY10 cast(lua_Unsigned, LUA_MAXINTEGER / 10)
#define MAXLASTD cast_int(LUA_MAXINTEGER % 10)

static const char *l_str2int(const char *s, lua_Integer *result)
{
  lua_Unsigned a = 0;
  int empty = 1;
  int neg;
  while (lisspace(cast_uchar(*s)))
    s++; /* skip initial spaces */
  neg = isneg(&s);
  if (s[0] == '0' &&
      (s[1] == 'x' || s[1] == 'X'))
  {         /* hex? */
    s += 2; /* skip '0x' */
    for (; lisxdigit(cast_uchar(*s)); s++)
    {
      a = a * 16 + luaO_hexavalue(*s);
      empty = 0;
    }
  }
  else
  { /* decimal */
    for (; lisdigit(cast_uchar(*s)); s++)
    {
      int d = *s - '0';
      if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg)) /* overflow? */
        return NULL;                                           /* do not accept it (as integer) */
      a = a * 10 + d;
      empty = 0;
    }
  }
  while (lisspace(cast_uchar(*s)))
    s++; /* skip trailing spaces */
  if (empty || *s != '\0')
    return NULL; /* something wrong in the numeral */
  else
  {
    *result = l_castU2S((neg) ? 0u - a : a);
    return s;
  }
}

size_t luaO_str2num(const char *s, TValue *o)
{
  lua_Integer i;
  lua_Number n;
  const char *e;
  if ((e = l_str2int(s, &i)) != NULL)
  { /* try as an integer */
    setivalue(o, i);
  }
  else if ((e = l_str2d(s, &n)) != NULL)
  { /* else try as a float */
    setfltvalue(o, n);
  }
  else
    return 0;         /* conversion failed */
  return (e - s) + 1; /* success; return string size */
}

int luaO_utf8esc(char *buff, unsigned long x)
{
  int n = 1; /* number of bytes put in buffer (backwards) */
  lua_assert(x <= 0x10FFFF);
  if (x < 0x80) /* ascii? */
    buff[UTF8BUFFSZ - 1] = cast(char, x);
  else
  {                          /* need continuation bytes */
    unsigned int mfb = 0x3f; /* maximum that fits in first byte */
    do
    { /* add continuation bytes */
      buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f));
      x >>= 6;                                          /* remove added bits */
      mfb >>= 1;                                        /* now there is one less bit available in first byte */
    } while (x > mfb);                                  /* still needs continuation byte? */
    buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x); /* add first byte */
  }
  return n;
}

/* maximum length of the conversion of a number to a string */
#define MAXNUMBER2STR 50

/*
** Convert a number object to a string
*/
void luaO_tostring(lua_State *L, StkId obj)
{
  char buff[MAXNUMBER2STR];
  size_t len;
  lua_assert(ttisnumber(obj));
  if (ttisinteger(obj))
    len = lua_integer2str(buff, sizeof(buff), ivalue(obj));
  else
  {
    len = lua_number2str(buff, sizeof(buff), fltvalue(obj));
#if !defined(LUA_COMPAT_FLOATSTRING)
    if (buff[strspn(buff, "-0123456789")] == '\0')
    { /* looks like an int? */
      buff[len++] = lua_getlocaledecpoint();
      buff[len++] = '0'; /* adds '.0' to result */
    }
#endif
  }
  setsvalue2s(L, obj, luaS_newlstr(L, buff, len));
}

static void pushstr(lua_State *L, const char *str, size_t l)
{
  setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
  luaD_inctop(L);
}

/*
** this function handles only '%d', '%c', '%f', '%p', and '%s'
   conventional formats, plus Lua-specific '%I' and '%U'
*/
const char *luaO_pushvfstring(lua_State *L, const char *fmt, va_list argp)
{
  int n = 0;
  for (;;)
  {
    const char *e = strchr(fmt, '%');
    if (e == NULL)
      break;
    pushstr(L, fmt, e - fmt);
    switch (*(e + 1))
    {
    case 's':
    { /* zero-terminated string */
      const char *s = va_arg(argp, char *);
      if (s == NULL)
        s = "(null)";
      pushstr(L, s, strlen(s));
      break;
    }
    case 'c':
    { /* an 'int' as a character */
      char buff = cast(char, va_arg(argp, int));
      if (lisprint(cast_uchar(buff)))
        pushstr(L, &buff, 1);
      else /* non-printable character; print its code */
        luaO_pushfstring(L, "<\\%d>", cast_uchar(buff));
      break;
    }
    case 'd':
    { /* an 'int' */
      setivalue(L->top, va_arg(argp, int));
      goto top2str;
    }
    case 'I':
    { /* a 'lua_Integer' */
      setivalue(L->top, cast(lua_Integer, va_arg(argp, l_uacInt)));
      goto top2str;
    }
    case 'f':
    { /* a 'lua_Number' */
      setfltvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));
    top2str: /* convert the top element to a string */
      luaD_inctop(L);
      luaO_tostring(L, L->top - 1);
      break;
    }
    case 'p':
    {                                    /* a pointer */
      char buff[4 * sizeof(void *) + 8]; /* should be enough space for a '%p' */
      void *p = va_arg(argp, void *);
      int l = lua_pointer2str(buff, sizeof(buff), p);
      pushstr(L, buff, l);
      break;
    }
    case 'U':
    { /* an 'int' as a UTF-8 sequence */
      char buff[UTF8BUFFSZ];
      int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long)));
      pushstr(L, buff + UTF8BUFFSZ - l, l);
      break;
    }
    case '%':
    {
      pushstr(L, "%", 1);
      break;
    }
    default:
    {
      luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
                    *(e + 1));
    }
    }
    n += 2;
    fmt = e + 2;
  }
  luaD_checkstack(L, 1);
  pushstr(L, fmt, strlen(fmt));
  if (n > 0)
    luaV_concat(L, n + 1);
  return svalue(L->top - 1);
}

const char *luaO_pushfstring(lua_State *L, const char *fmt, ...)
{
  const char *msg;
  va_list argp;
  va_start(argp, fmt);
  msg = luaO_pushvfstring(L, fmt, argp);
  va_end(argp);

  printf("%s", msg);

  return msg;
}

/* number of chars of a literal string without the ending \0 */
#define LL(x) (sizeof(x) / sizeof(char) - 1)

#define RETS "..."
#define PRE "[string \""
#define POS "\"]"

#define addstr(a, b, l) (memcpy(a, b, (l) * sizeof(char)), a += (l))

void luaO_chunkid(char *out, const char *source, size_t bufflen)
{
  size_t l = strlen(source);
  if (*source == '=')
  {                   /* 'literal' source */
    if (l <= bufflen) /* small enough? */
      memcpy(out, source + 1, l * sizeof(char));
    else
    { /* truncate it */
      addstr(out, source + 1, bufflen - 1);
      *out = '\0';
    }
  }
  else if (*source == '@')
  {                   /* file name */
    if (l <= bufflen) /* small enough? */
      memcpy(out, source + 1, l * sizeof(char));
    else
    { /* add '...' before rest of name */
      addstr(out, RETS, LL(RETS));
      bufflen -= LL(RETS);
      memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
    }
  }
  else
  {                                        /* string; format as [string "source"] */
    const char *nl = strchr(source, '\n'); /* find first new line (if any) */
    addstr(out, PRE, LL(PRE));             /* add prefix */
    bufflen -= LL(PRE RETS POS) + 1;       /* save space for prefix+suffix+'\0' */
    if (l < bufflen && nl == NULL)
    {                         /* small one-line source? */
      addstr(out, source, l); /* keep it */
    }
    else
    {
      if (nl != NULL)
        l = nl - source; /* stop at first newline */
      if (l > bufflen)
        l = bufflen;
      addstr(out, source, l);
      addstr(out, RETS, LL(RETS));
    }
    memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
  }
}
